package example;

import org.w3c.dom.ls.LSOutput;

import java.io.*;
import java.util.Scanner;

//实现递归遍历目录,查找文件(按文件内容查找)
public class demo19 {


    public static void main(String[] args) {
        Scanner scanner= new Scanner(System.in);
        System.out.println("请输入要搜索的路径:" );
        String rootPath = scanner.next();
        File rootFile = new File(rootPath);
        if(!rootFile.isDirectory()){
            System.out.println("要搜索文件有误!");
            return;
        }
        System.out.println("请输入要搜索的查询词: ");
        String key = scanner.next();

        //递归
        scan(rootFile,key);
    }
    private static void scan(File rootFile, String key){
        if(!rootFile.isDirectory()){
            return;
        }
        File[] files = rootFile.listFiles();
        if(files == null || files.length == 0){
            return;
        }
        for(File f : files){
            if(f.isFile()){
                //进行后续查询操作
                doSearch(f,key);

            }else {
                //递归
                scan(f,key);
            }
        }
    }
    private static void doSearch(File f, String key) {
        //打开文件,读取文件内容,判定文件内容是否包含key
        StringBuilder stringBuilder = new StringBuilder();
        try(Reader reader = new FileReader(f)){

            char[] buffer = new char[1024];
            while (true){
                int n = reader.read(buffer);
                if(n == -1){
                    break;
                }
                String s= new String(buffer,0,n);
                stringBuilder.append(s);
            }
        }catch (IOException e){
            e.printStackTrace();
        }
        if(stringBuilder.indexOf(key) == -1){
            //未找到
            return;
        }
        //找到了
        System.out.println("找到匹配的文件:" + f.getAbsolutePath());
    }

}
